Process for treating silica.



l. ROSENBLUM.

PROCESS FOR TREATING SILICA.

APPLICATION FILED MAR. SII 1.911.

1,229,324. Patented June 12, 1917.

ISRAEL ROSENBLUM, OF SWAMPSGOT'I, MASSACHUSETTS.

PROCESS FOR TREATING S'ILICA.

Specification of Letters Patent. Patented Jlllle 12; 1917-.'

Application filed March 31, 1917. Serial No. 158,958.

To all 'wlwm it may concern:

Be it known that I, ISRAEL ROSENBLUM, a subject of the King of Roumania, residing at Swampscott, in the county of Essex and State of Massachusetts', have invented certain newand useful Improvements in Processes for Treating Silica, ofwhich the following is a specification.

My invention relates to the production of articles from molten quartz or pure silica and has for its objectthe production of silica articles made therefrom in relatively large pieces free from any impurities.

Another object of my invention is the cheapening of the production of articles made from quartz as at present same are made in crucibles of iridium or similar ,costly metals in small quantities in which the cost of production is necessarily high.

A further object of my invention is-the production of completed quartz articles in a pure condition in the form of rods, tubes, crucibles, beakers and containers of various sizes.

Itis well known that by heating quartz in an electric furnace in a graphite Crucible, to

a temperature where quartz is plastic, the

.quartz is contaminated by the carbon chemically'as well as mechanically. It is therefore impossible to obtain pure transparent quartz in the ordinary manner in graphite crucibles.

I have discovered that if a transparent yquartz tube is slipped over a graphite rod and heated to a temperature between 1400 degrees centigrade to 1600 degrees centigrade in a nitrogen atmosphere, a compound of silicon, nitrogen and carbon is formed which acts as a protective coating over the graphite rod and prevents further action on the graphi ite by the quartz. As the melting point of the compound of silicon, nitrogen and carbon when once -formed is far above the tem erature needed to render the quartz p astic vwhich is about 1800 degrees centigrade, it

follows that 'this compound acts as a protective layer not permlttingthe quartz to be contaminated by the grap 1te.

Taking advantage-of t e discovery of the and carbon whic as a very high meltmg point and does notreact withlquartz at temperatures where quartz isplastic and "protectshthev graphite from further action und of silicon nitroupon quartz, I have developed a cheap method for manufacturing pure transparentquartz in graphite crucibles, in a nitrogen atmosphere.

In practice, after the.v initial protective coating has been formed, instead of nitrogen, illuminating gas or other inert gases. may be used. When the'quartz is thus in a 'liquid state free from bubbles and free from impurities, I am then enabled to work same in the ordinary manner by blowing, pressing' drawing or by other known methods by which molten silica can be operated upon.

I -iind however that in this process I can vobtain relatively largermasses of pure silica to operate with than in the bo k lprocesses hither nown.

Figure 1 is a sectional view of an apparatus showing the operation of my invention, and e Fig. 2 is an enlarged sectional view of the graphite Crucible showing the thin layer of protective coating which prevents the contamination of the quartz by the body of the crucible. '2

1 is a graphite crucible; 2 is the protective lining formed by interaction of nitrogen,

lcarbon of the crucible, and quartz-vapors; 3

represents the mass of quartz to be operated upon.; 4 represents the piping conveying the current of nitrogen; 5 represents a graphite chamber with cover through which the conveying pipesya'rrive; 6 represents.. the graphite Wall of the electric furnace; 7 represents the graphite water cooled electrodes of the furnace; 8 represents the coke or graphite particles with which the electric furnace is packed; and 9 represents the outer limng of the electric furnace.

What I claim is l 1. A process bf treating quartz in an electric furnace in a graphite. Crucible in the presence of oxygen-free nitrogen gas.

2. A process of treating quartz 1n an electric furnace in-a Crucible containing carbon in the presence f oxygen-free nitrogen.

c 3. A rocess of treating uartz in a graphite cruciblein an electric material to be treated and the lining of the crucible and then raising the temperature for the liq'uefaction of the quartz.-

rnace by forml, ing protective layer on said cruclble through Ythe interaction of a portionof the 4. A process of preparing a composition,

of matter by subjecting carbon to the action 6. A process of producing a new composiof quartz in an electric furnace in the prestion of matter by treating quartz in a graph- 10 ence of oxygen-free nitrogen gas. ite crucible in an electric furnace from 1400 5. A process of produclng a composition to 1700 degrees centigrade in the presence of 5 of matter by subjecting carbon to the action oxygen-free nitro en gas.

of quartz 1n the presence of oxygen-free In testimony W ereof I hereunto ax my nitrogen gas at a temperature of approxisignature. mately 1600 degrees centigrade. ISRAEL ROSENBLUM. 

